The first major step in the cheese making process is the coagulation of the milk by enzymatic hydrolysis of κ-casein. To achieve this end, enzyme extracts from calf stomachs, microbialy produced enzymes or other enzymes are utilized. The hydrolysis of κ-casein leads to destabilization of the colloidal system of the milk. This is followed by aggregation of the micelles into clusters. Over time, the clusters grow in size. This growth in size is followed by cross-linking between chains which eventually transform the milk into a gel or coagulum. Once a desired point is reached in the coagulation process, the coagulum is “cut” by traversing with wire knives to slice the coagulum into approximately 0.7 cm cubes.
Syneresis is the phase separation process in cheese making that follows the cutting of the milk coagulum into cubes. Syneresis is generally promoted by thermal and/or mechanical treatments. During syneresis, rearrangement of casein network, constituting the gel matrix, causes the shrinkage of the curd matrix and results in expulsion of whey from the curd grains.
Syneresis control influences cheese quality and yield as a result of its effects on moisture, mineral and lactose content of the curd. Syneresis also influences protein and fat loses in whey, which in turn affects cheese yield.
Despite its importance, syneresis is one of the least understood phases in the cheese making process, especially from both a physical/chemical and kinetic prospective. The kinetics of curd syneresis is complex and there are no technologies currently available for monitoring it. At present, in the cheese industry worldwide, syneresis is empirically controlled by vat temperature, milk pH, stirring speed and time, depending on cheese type and the cheese maker's preferences. Inadequate curd moisture control will lead to heterogeneous cheese ripening and quality. Better control of syneresis would give more consistent curd moisture content and pH, and more consistent curd concentration of minerals and lactose at the beginning of the curing process.
It has been found that syneresis is a first order kinetics reaction. As a consequence, one can predict the syneresis end point with some confidence.
The present invention relates to a method of improving the quality of cheese produced from a curd and whey mixture. More specifically, the present method provides improved syneresis control to ensure moisture content consistency and better cheese quality.